Continuous concrete mixer

ABSTRACT

A continuous concrete mixer in which a concrete mix, including water, if fed continuously into one end of a horizontal tubular drum and the prepared concrete is continuously discharged from the other end of the drum; the drum being rotatably mounted on a semitrailer chassis and contains a continuous helical conveying blade joined to the walls of the drum and to a central tube; there being mixing blades extending from the drum wall into the space between the convolutions of the conveying blades.

United States Patent Inventor Robert E. Jackson New Port Beach, Calif. Appl. No. 763,167 Filed Sept. 27, 1968 Patented Jan. 26, 1971 Assignee Challenge-Cook Bros., Incorporated lndustry, Calif. a corporation of California CONTINUOUS CONCRETE MlXER 9 Claims, 3 Drawing Figs.

US. Cl 259/177,

259/3 Int. Cl B28c 5/18 Field of Search 259/175,

References Cited UNITED STATES PATENTS 2/1934 Jaeger 259/177 12/1912 Tiedtke.. 259/15 11/1949 McEachran 259/176 11/1957 Erren 259/175 Primary ExaminerRobert W. Jenkins Attorney-Lyon & Lyon ABSTRACT: A continuous concrete mixer in which a concrete mix, including water, if fed continuously into one end of a horizontal tubular drum and the prepared concrete is continuously discharged from the other end of the drum; the drum being rotatably mounted on a semitrailer chassis and contains a continuous helical conveying blade joined to the walls of the drum and to a central tube; there being mixing blades extending from the drum wall into the space between the convolutions of the conveying blades.

PATENTEU JAN26 1971 3558.108

sum 2 0F 2 505527 Ewe/(50m INVENTOR.

CONTINUOUS CONCRETE MIXER BACKGROUND AND SUMMARY OF THE INVENTION The typical concrete mixer is a batch mixer; that is, a measured quantity of concrete mix is placed in the mixer. sometimes with water, sometimes initially dry, the water being added; later, after a predetermined interval, the batch is discharged. If a large quantity of concrete is required, such as may occur in the construction of dams, large canal projects, aircraft runways and freeways, the batch mixer is too slow or too many mixers and their crews are required.

The present invention provides a means for supplying the prepared concrete continuously at a much faster rate than is possible with a batch-type mixer; more particularly, the objects of this invention are:

First, to provide a continuous concrete mixer which may be mounted on a semitrailer for mo'vement from one site to another, yet is capable of supplying mixed concrete at a rate in the order of I ,000 cubic yards per hour.

Second, to provide a continuous-concrete mixer in which the ingredients are received at one end, conveyed continuously to the other end, and while being conveyed are mixed by paddle blades which lift then dump the material in repeated sequence so as to accomplish a thorough mixing by the time the material reaches the discharge end.

Third, to provide a continuous concrete mixer in which there is a minimum of wastage at the start and at the conclusion of a concrete mixing run.

DESCRIPTION OF THE FIGURES FIG. 1 is a side view of the continuous concrete mixer, with a portion of the wall removed to illustrate the internal construction and a portion in section, and with alternate mixer blades removed to simplify the illustration.

FIG. 2 is an enlarged fragmentary sectional view, taken through 2-2 of FIG. 1, showing one of the drive and supporting means.

FIG. 3 is an enlarged partially end view, partially sectional view, taken through 33 of FIG. 1.

SPECIFICATION The continuous concrete mixer is mounted on a semitrailer chassis 1, having wheels 2, provided at its forward end with a removable towing yoke 3, indicated by broken lines. When the mixer is in use and the towing yoke 3 is removed, the forward end of the chassis l rests on a suitable support 4.

The chassis is provided with a pair of transverse supporting frames 5, on which is mounted a pair of bearings 6, provided with drum supporting rollers 7. Each cross frame supports a thrust roller 8.

A cylindrical drum 9 is provided, having a receiving end I0, provided with a central opening 11, and a tapered discharging end 12. The drum is provided with a pair of annular roller tracks I3, which rest on the rollers 7. Each track is provided with a thrust flange l4, engaged by a-corresponding thrust roller 8 which bear in opposite directions so that the drum is free to rotate, but is restrained against axial displacement.

Adjacent each roller track 13, the drum is provided with a ring gear 15, engaged by a drive gear 16, driven by a suitable gear motor 17. The two motors thus provided are mounted on the chassis l.

Internally, the drum 9 is provided with a helical conveying blade 18, extending from the receiving end 10 to the discharging end 12. The helical blade is placed around a central longitudinally extending tube 19 and forms at the bottom portion of the drum a series of mixing compartments 20, which advance towards the discharging end as the drum rotates.

Mounted between the convolutions of the conveying blade 18 is a series of mixing units 21, which are comprised of a pair of mounting brackets 22 extending inwardly from the wall of the drum 9, and a pair of mixing blades 23 secured to the brackets in radial relation. It is preferred to provide eight mixing units per convolution; however, in order to simplify the illustration, alternate mixing units are omitted in FIG. I.

A feed hopper 24 is mounted on a supporting frame 25 in front of the receiving end 10 of the drum. The feed hopper is provided with a discharge spout 26 which extends into the central opening II. In order to accommodate the discharge spout and to receive the material flowing from the hopper, the central tube 19 terminates short ofthe receiving end.

Operation of the continuous concrete mixer is as follows:

The components of the concrete mixture including the water are introduced through the hopper 23. The helical blade 18 advances the mixture toward the discharging end 12. In its progress toward the discharging end, the mixture is repeatedly picked up by the mixing units 21 and as the mixing units rotate about the axis of the drum, the mixture is dumped or poured back into the body of the mixture at the bottom of the drum with the result that the ingredients are thoroughly mixed as the concrete approaches the discharging end.

Attention is directed to FIG. 3 which indicates by dash line the body of concrete which is maintained well below the height or radial depth of the helical blade. Stated otherwise. the radial depth of the convolutions is substantially greater than the radial height of the concrete as well as the radial dimension of the mixing units 21. 7

As a result, the concrete in each convolution remains separated from the concrete in the other convolutions; that is, even if the central tube 19 were omitted, spillover between adjacent convolutions is virtually eliminated.

It should be noted that, if desired, water may be introduced intermediate the ends of the drum; for example, through the central tube 19 so that the dry concrete ingredients may be premixed before water is added.

While particular embodiments of this invention have been shown and described, it is not intended to limit the same to the details of the constructions set forth, but instead, the invention embraces such changes, modifications and equivalents of the various parts and their relationships as come within the purview of the appended claims,

I claim:

1. A continuous concrete mixer, comprising:

a. An essentially horizontal drum having an end for receiving concrete ingredients and an end for discharging mixed concrete;

. a continuous helical conveying blade within said drum extending between said receiving end and said discharging end, said blade having a multiplicity of convolutions;

c. a series of mixing blade units extending between the convolutions of said conveying blade for repeated lifting and dumping of the concrete mixture during progress of the concrete from said receiving end to said discharging end; means for rotating said drum about its longitudinal axis; and

. a central tube connecting the convolutions'of said conveying blade to confine the concrete to the peripheral portions of said drum.

2. A continuous concrete mixer, as defined in claim I, wherein:

a. said central tube terminates short of the receiving end of said drum, said receiving end is closed by a plate having a central aperture; and

b. a hopper is mounted at said receiving end and terminates in a discharge spout extending into said aperture.

3. A continuous concrete mixer, as defined in claim I, wherein each of said mixing blade units includes at least a pair of blade members extending transversely between the convolutions of said conveying blade and bracket members, disposing said blade members in radial relation.

4. A continuous concrete mixer, as defined in claim I, wherein said rotating means includes:

a. a pair of spaced roller tracks and thrust flanges mounted on said drum;

b. a supporting frame;

c. sets of supporting rollers and corresponding thrust rollers carried by said frame and engaging said roller tracks and said thrust flanges;

d. at least one ring gear on said drum; and

e. at least one drive gear and motor therefor carried by said frame.

5. A continuous concrete mixer. as defined in claim 4. wherein said supporting frame is a semitrailer having transporting wheels. and includes a towing yoke at the discharging end of said drum, said yoke being removable to clear said discharging end.

6. A continuous concrete mixer for taking a continuous supply of concrete ingredients in proper proportion and thoroughly mixing the ingredients for a predetermined period of time while retaining such proportions, comprising, an elongated drum mounted for relatively horizontal rotation on the drum axis and having one end open for receiving the concrete ingredients and the other end open for discharging the mixed concrete, helical blade means mounted within the drum for conveying the concrete along the drum between said open ends as the drum is rotated, said helical blade means having a multiplicity of convolutions forming separate mixing compartments between convolutions at the lower portion of the drum, and means for rotating said drum at a predetermined rate relative to the rate of supply of concrete ingredients to allow only partial filling of said drum to a radial depth less than the radial depth of helical blade. thereby providing a quantity of concrete ingredients in each mixing compartment and maintaining the ingredient proportions as the concrete is conveyed from one drum end to the other with the drum rotation relative to each said quantity of concrete causing agitation and mixing.

7 The concrete mixer ofclaim 6 wherein mixing blades olja lesser radial depth than the helical blade are mounted in the drum for causing lifting and dumping ol the concrete within each mixing compartment as the drum is rotated.

8. The concrete mixer ol claims 6 wherein a central tube is mounted concentrically within the drum and the helical blade means span the annular space between the drum and central tube.

9. A continuous concrete mixer, comprising:

a. an essentially horizontal drum having an end for receiving concrete ingredients and an end for discharging mixed concrete;

b. a continuous helical conveying blade within said drum extending between said receiving end and said discharging end. said blade having a multiplicity of convolutions and having a radial dimension greater than the radial dimen sion of concrete ingredients received in each convolution;

c. a series of mixing blade units extending between the convolutions of said conveying blade for repeated lifting and dumping of the concrete mixture during progress of the concrete from said receiving end to said discharging end. the radial dimension of the conveying blade being such as to maintain separated the concrete ingredients in each convolution; and

d. means for rotating said drum about its longitudinal axis. 

1. A continuous concrete mixer, comprising: a. An essentially horizontal drum having an end for receiving concrete ingredients and an end for discharging mixed concrete; b. a continuous helical conveying blade within said drum extending between said receiving end and said discharging end, said blade having a multiplicity of convolutions; c. a series of mixing blade units extending between the convolutions of said conveying blade for repeated lifting and dumping of the concrete mixture during progress of the concrete from said receiving end to said discharging end; d. means for rotating said drum about its longitudinal axis; and e. a central tube connecting the convolutions of said conveying blade to confine the concrete to the peripheral portions of said drum.
 2. A continuous concrete mixer, as defined in claim 1, wherein: a. said central tube terminates short of the receiving end of said drum, said receivinG end is closed by a plate having a central aperture; and b. a hopper is mounted at said receiving end and terminates in a discharge spout extending into said aperture.
 3. A continuous concrete mixer, as defined in claim 1, wherein each of said mixing blade units includes at least a pair of blade members extending transversely between the convolutions of said conveying blade and bracket members, disposing said blade members in radial relation.
 4. A continuous concrete mixer, as defined in claim 1, wherein said rotating means includes: a. a pair of spaced roller tracks and thrust flanges mounted on said drum; b. a supporting frame; c. sets of supporting rollers and corresponding thrust rollers carried by said frame and engaging said roller tracks and said thrust flanges; d. at least one ring gear on said drum; and e. at least one drive gear and motor therefor carried by said frame.
 5. A continuous concrete mixer, as defined in claim 4, wherein said supporting frame is a semitrailer having transporting wheels, and includes a towing yoke at the discharging end of said drum, said yoke being removable to clear said discharging end.
 6. A continuous concrete mixer for taking a continuous supply of concrete ingredients in proper proportion and thoroughly mixing the ingredients for a predetermined period of time while retaining such proportions, comprising, an elongated drum mounted for relatively horizontal rotation on the drum axis and having one end open for receiving the concrete ingredients and the other end open for discharging the mixed concrete, helical blade means mounted within the drum for conveying the concrete along the drum between said open ends as the drum is rotated, said helical blade means having a multiplicity of convolutions forming separate mixing compartments between convolutions at the lower portion of the drum, and means for rotating said drum at a predetermined rate relative to the rate of supply of concrete ingredients to allow only partial filling of said drum to a radial depth less than the radial depth of helical blade, thereby providing a quantity of concrete ingredients in each mixing compartment and maintaining the ingredient proportions as the concrete is conveyed from one drum end to the other with the drum rotation relative to each said quantity of concrete causing agitation and mixing.
 7. The concrete mixer of claim 6 wherein mixing blades of a lesser radial depth than the helical blade are mounted in the drum for causing lifting and dumping of the concrete within each mixing compartment as the drum is rotated.
 8. The concrete mixer of claims 6 wherein a central tube is mounted concentrically within the drum and the helical blade means span the annular space between the drum and central tube.
 9. A continuous concrete mixer, comprising: a. an essentially horizontal drum having an end for receiving concrete ingredients and an end for discharging mixed concrete; b. a continuous helical conveying blade within said drum extending between said receiving end and said discharging end, said blade having a multiplicity of convolutions and having a radial dimension greater than the radial dimension of concrete ingredients received in each convolution; c. a series of mixing blade units extending between the convolutions of said conveying blade for repeated lifting and dumping of the concrete mixture during progress of the concrete from said receiving end to said discharging end, the radial dimension of the conveying blade being such as to maintain separated the concrete ingredients in each convolution; and d. means for rotating said drum about its longitudinal axis. 